feat(android): do not use sync.Mutex

pkg/browser/gioui/browser.go

@@ -2,7 +2,7 @@ package gioui
 
 import (
 	"context"
-	"sync"
+	"sync/atomic"
 
 	"forge.cadoles.com/arcad/arcast/pkg/browser"
 	"gioui.org/app"
@@ -16,26 +16,20 @@ type Browser struct {
 	window *app.Window
 	tag    int
 
-	url     string
-	changed bool
-
-	status browser.Status
-	title  string
-
-	mutex sync.Mutex
+	url     *atomic.Value
+	changed *atomic.Bool
+	status  *atomic.Value
+	title   *atomic.Value
 }
 
-func (b *Browser) Layout(gtx layout.Context) {
-	b.mutex.Lock()
-	defer b.mutex.Unlock()
-
+func (b *Browser) Layout(gtx layout.Context) layout.Dimensions {
 	events := gtx.Events(&b.tag)
 	for _, evt := range events {
 		switch ev := evt.(type) {
 		case webviewer.TitleEvent:
-			b.title = ev.Title
+			b.title.Store(ev.Title)
 		case webviewer.NavigationEvent:
-			b.url = ev.URL
+			b.url.Store(ev.URL)
 		}
 	}
 
@@ -58,21 +52,20 @@ func (b *Browser) Layout(gtx layout.Context) {
 		},
 	}.Add(gtx.Ops)
 
-	if b.changed {
-		logger.Debug(ctx, "url changed", logger.F("url", b.url))
-		webviewer.NavigateOp{URL: b.url}.Add(gtx.Ops)
-		b.changed = false
+	if b.changed.CompareAndSwap(true, false) {
+		url := b.url.Load().(string)
+		logger.Debug(ctx, "url changed", logger.F("url", url))
+		webviewer.NavigateOp{URL: url}.Add(gtx.Ops)
 	}
+
+	return layout.Dimensions{Size: gtx.Constraints.Max}
 }
 
 // Load implements browser.Browser.
 func (b *Browser) Load(url string) error {
-	b.mutex.Lock()
-	defer b.mutex.Unlock()
-
-	b.url = url
-	b.changed = true
-	b.status = browser.StatusCasting
+	b.url.Store(url)
+	b.changed.Store(true)
+	b.status.Store(browser.StatusCasting)
 
 	b.window.Invalidate()
 
@@ -81,36 +74,24 @@ func (b *Browser) Load(url string) error {
 
 // Status implements browser.Browser.
 func (b *Browser) Status() (browser.Status, error) {
-	b.mutex.Lock()
-	defer b.mutex.Unlock()
-
-	return b.status, nil
+	return b.status.Load().(browser.Status), nil
 }
 
 // Title implements browser.Browser.
 func (b *Browser) Title() (string, error) {
-	b.mutex.Lock()
-	defer b.mutex.Unlock()
-
-	return b.title, nil
+	return b.title.Load().(string), nil
 }
 
 // URL implements browser.Browser.
 func (b *Browser) URL() (string, error) {
-	b.mutex.Lock()
-	defer b.mutex.Unlock()
-
-	return b.url, nil
+	return b.url.Load().(string), nil
 }
 
 // Reset implements browser.Browser.
 func (b *Browser) Reset(url string) error {
-	b.mutex.Lock()
-	defer b.mutex.Unlock()
-
-	b.url = url
-	b.changed = true
-	b.status = browser.StatusIdle
+	b.url.Store(url)
+	b.changed.Store(true)
+	b.status.Store(browser.StatusIdle)
 
 	b.window.Invalidate()
 
@@ -118,12 +99,20 @@ func (b *Browser) Reset(url string) error {
 }
 
 func NewBrowser(window *app.Window) *Browser {
-	return &Browser{
+	b := &Browser{
 		window:  window,
-		url:     "",
-		changed: true,
-		status:  browser.StatusIdle,
+		url:     &atomic.Value{},
+		changed: &atomic.Bool{},
+		status:  &atomic.Value{},
+		title:   &atomic.Value{},
 	}
+
+	b.url.Store("")
+	b.title.Store("")
+	b.changed.Store(false)
+	b.status.Store(browser.StatusIdle)
+
+	return b
 }
 
 var _ browser.Browser = &Browser{}